The present invention is directed generally to the handling of waste ink accumulated in an ink jet printer system, and more particularly, to an apparatus and method for increasing the effective capacity for storing waste ink in a maintenance station without increasing the physical capacity of the waste ink collection reservoir.
Ink jet printers require maintenance operations to keep the nozzles of the print cartridge operating properly. Such maintenance operations typically include a combination of wiping the nozzle area of the print cartridge, firing the nozzles at prescribed intervals (spitting), and capping the cartridge during idle periods to prevent the jetted ink which remains on the nozzle plate from drying and clogging one or more of the nozzles of the nozzle plate. Typically, the spitting operation occurs at a location in the maintenance station. Over a period of time, the solids in the waste ink accumulate in the maintenance station, and the resulting waste ink build-up can affect the operation of the maintenance assembly.
Various attempts have been made to handle and transfer waste ink in an ink jet system. One such attempt is directed to an apparatus having a pump mechanism for carrying waste ink from the pump to a carrying member. Waste ink is supplied to the pump by a series of ink-absorbing materials which, by capillary action, transfer the waste ink to the pump. During operation, a print head wiper slides in contact with a wipe-over portion of an ink-absorbing member carried by an ink-absorbing spring at a predetermined position on the chassis, whereby ink, water droplets, and contaminants adhering to the wiper are imparted to the ink-absorbing member. The ink or water droplets adhering to the ink-absorbing members transfer from one member to another by capillary action, and ultimately to the pump mechanism for carrying waste ink from the pump to a waste ink carrying member.
Early ink jet printers used dye-based inks, which were mostly volatile liquids, and the maintenance operations required little capacity for waste ink generated from the spitting operation due to evaporation of the volatile liquid component of the ink and the relatively small quantity of solids in the ink. More recent products, however, have incorporated pigment-based inks that have a larger percentage of solids in them. After the volatile components evaporate, a sludge of mostly solid material is left behind. This solid material builds up in or below the maintenance assembly, and over time, storage capacity must be provided for the solid buildup in order for the maintenance station of the printer to operate properly. To address this increase in capacity, one method would be to increase the size of the waste ink collection reservoir for collecting the waste ink. Such an increase in capacity for collecting waste ink, however, would result in increased size of the printer and/or increased cost relating to the increased capacity for the waste ink collection reservoir.
Accordingly, a need exists for a printing system which includes a maintenance station which has the ability to effectively increase the amount of waste ink which can be collected without physically increasing the size of the waste ink collection reservoir.
The present invention is directed to apparatus and method for effectively increasing the waste ink capacity of an ink printing device, such as an ink jet printer, without the necessity of increasing the size of the waste ink collection reservoir of the ink printing device. The apparatus includes a spreader mechanism coupled to a drive mechanism of the ink printing device, wherein the spreader mechanism is driven by the drive mechanism to engage and disperse waste ink over a waste ink accumulation region.
In one embodiment of the invention, a maintenance unit is disclosed for use in an ink jet printer, wherein the ink jet printer includes a printer frame having a waste ink accumulation region. The maintenance unit includes a maintenance frame coupled to the printer frame, a maintenance sled moveably coupled to the maintenance frame, and a spreader mechanism coupled to the maintenance sled. The spreader mechanism disperses waste ink over the waste ink accumulation region as the maintenance sled moves relative to the maintenance frame.
Preferably, the spreader mechanism includes an elongate portion and a drive pin extending from the elongate portion, and the maintenance sled includes an aperture for receiving the drive pin of the spreader mechanism. In addition, the printer frame includes a pivot pin and the spreader mechanism rotates about the pivot pin due to a movement of the maintenance sled relative to the maintenance frame to disperse waste ink over the waste ink accumulation region.
Other features and advantages of the invention may be determined from the drawings and the detailed description of the invention that follows. Corresponding reference characters indicate corresponding elements throughout the several figures.